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Alternate Hemibody Irradiation (AHBI) is a new effective treatment method for leukemia and malignant lymphoma. Hematopoietic reconstruction could be performed without marrow transplantation with AHBI. But the dose uniformity in the whole body of AHBI was not perfect. To prepare for clinical AHBI, we measured the dose distribution in vivo with standard phantom. According to the data, we want to choice better radiation condition and seek the suitable dividing line of the upper and lower beam field. Under clinical AHBI conditions, the dose measurement of standard phantom was performed with TLD-100. The dose distribution of cerebrum, ocular lens, esophagus, lung, heart, liver, spleen, small intestine, pancreas, kidney, abdominal vertebra, didymus, and bladder was measured exactly. The lung and ocular lens were shielded necessarily according to the clinical requirement. The dose distribution of the upper and lower beam field was measured with four methods of dividing line. The upper and lower beam field was designed as following: (1) 2 beam fields connected, (2) 2 beam fields overlapped for 1cm, (3) 2 beam fields overlapped for 2cm, (4) 2 beams field separated for 1cm. Eleven patients with acute leukemia and six patients with malignant lymphomas were treated with AHBI combined with high-dose chemotherapy. 14 days (range, 12-22days) after high-dose chemotherapy, Upper Hemibody Irradiation was performed in a dose of 8Gy, while the dose of lung is less than 6Gy. An interval of 23(7-34) days later, lower hemibody irradiation (9Gy) was given. The homogeneity of dose distribution in phantom was within ±15%. A suitable dividing line of the upper and lower beam field was found, which can avoid overdosage or less dosage of the overlap. Hematopoietic reconstruction was observed in all of the patients. AHBI in leukemia and malignant lymphoma therapy is a feasible approach. [ABSTRACT FROM AUTHOR]